PO-TAS-SI-UM

The first element of the fourth row (period) is potassium. The name potassium comes from a substance called Potash. That compound that has been used for hundreds of years and has the chemical formula KOH. Even though we have been using potash for centuries, Davy officially discovered potassium in 1807. In fact, potassium is never found by itself in nature. It is always bonded to other elements. Once isolated, Davy found potassium to be one of the softer metals with a silver color.

Potassium is a little tricky to remember on the periodic table because the symbol is "K". Like sodium (Na) and gold (Au), the symbol is not an abbreviated form of the element's English name. We know where the English name potassium came from, but what about that "K"? The K represents the word Kalium. It is an older term used to describe the element and has its origins in the word "alkali." Like other elements in the first column, potassium is a member of the alkali group with sodium and cesium.

Where can you find potassium?

Bananas
Did your mom ever to tell you to eat bananas because they're good for you? It was probably all of the potassium that made her say that. Potassium is an important element found in many foods.

Crust of the Earth
As far as individual elements are concerned, 2.4% of the Earth's crust is made of potassium atoms. The element is bonded to many other elements and found in almost all rocks.

Fireworks
That's right. Potassium is one of the many elements found in fireworks and pyrotechnics of all kinds.

Fertilizer
Plants love potassium and need it in the same way that animals do. The potassium is absorbed and used throughout plant organelles.

Oceans
You'll find loads of potassium in the world's oceans. Because potassium forms salts so easily, many of the ions in salt water are potassium ions. You may even find trace amounts in freshwater sources.

Nuclear Reactors
As you learn more about chemistry, you will learn that many of the simple elements are involved in nuclear reactors and radioactive experiments. You can even find radioactive isotopes of potassium that are used in research.